Adiabatic Chiral Magnetic Effect in Weyl semimetal wires

TL;DR

This paper investigates the adiabatic chiral magnetic effect in Weyl semimetal wires, revealing how boundaries influence the phenomenon and providing a formula to describe it based on energy levels.

Contribution

It introduces a simple formula to describe the boundary-influenced adiabatic CME using energy levels, extending previous theoretical insights.

Findings

Boundary effects significantly alter the CME

Derived a formula linking CME to energy levels

Analyzed a boundary-defined example of CME

Abstract

The Chiral Magnetic Effect (CME) is a phenomenon by which an electric current develops in the direction of a magnetic field applied to a material. Recent theoretical research suggests that the CME can be observed in thermal equilibrium provided that the magnetic field oscillates with finite frequency $\omega$. Moreover, under certain conditions the amplitude of the electric current does not vanish in the adiabatic $\omega \to 0$ limit, which we call here the adiabatic CME. In this work, we consider an adiabatic CME in a bounded sample. We demonstrate that the presence of the boundary significantly changes the nature of the effect. Using linear response theory, we derive a simple formula (conjectured earlier in arXiv:1512.02144) that enables us to describe the CME in a bounded setting based on the knowledge of the energy levels alone. We use this formula to investigate a particularly interesting example of the CME completely defined by the boundary effects.